等温淬火球墨铸铁的组织与旋转弯曲疲劳性能

研究了一种ｃｕ－Ｍｏ球墨铸铁经６４３Ｋ、６１３Ｋ与５５３Ｋ等温淬火后的旋转弯曲疲劳性能与组织。结果表明，等温淬火球墨铸铁的疲劳寿命随塑性的上升与强度的下降而增高。具有奥贝基体的试样有着优秀的疲劳性能。这与文献中报导的结果一致。讨论了试样的组织与疲劳寿命的关系，指出球铁中的奥贝组织与大多数钢中的上贝氏体不同，因而等温淬火后球铁与钢的疲劳强度的变化具有相反的规律。

The Structure and Rotating Bending Fatigue of an Austempered Ductile Iron

Specimens rnade from a Cu-Mo ductile iron were austempered at 643K,613K and 553K. Theirrotating bending fatigue properties and structure were studied.The results obtained show that the fatiguelife of austempered ductile iron increases with the increase of ductility and decrease of tensile strength.Specimens with austenitic-bainitic matrices exhibit higher endurance limit,which is consistent with the datareported in the literature,A discussion correlating the structure and the fatigue life is presented,explainingthe contrary dependence of fatigue life with strength and ductility in austempered ductile irons and moststeels is due to the substantial difference between the upper bainites formed in the two materials.